The United ground stop has been lifted at airports in multiple cities as the airline resolved a technical issue. There are still residual delays.

United Airlines resolved a “technology issue” that triggered a ground stop for the carrier’s flights at major U.S. airports Wednesday evening that led to hundreds of delays and some cancelations, although the airline was still tackling residual delays triggered by the outage.

The system outage to United Airlines occurred last night at 8pm triggering the ground stop. The domino effect of delays could be seen at Tampa International Airport this morning. United Airlines is calling the incident a technology issue and treating it as a controllable delay.